Stormwater overview

When the combined sewer and stormwater system is overwhelmed, pollution flows into our rivers and raw sewage can back up into basements. In other words, a failing stormwater system is a public health and safety issue. In 2017, pollution flowed into our rivers more than 60 times because the combined system couldn’t handle the volume of water. PWSA’s stormwater projects will capture and collect rain water – and treat it on site – so it doesn’t immediately flow into the sewer system, mix with sewage, and overflow into a basement.

Managing stormwater is challenging and costly, but because PWSA is publicly-owned we can focus on doing what is right, for the long term, not for what might be most expedient or profitable now. That means pursuing green solutions to stormwater problems that are financially and environmentally sustainable. We’re focusing on critical areas so that we can turn today’s biggest flooding and sewer backup risks into tomorrow’s cleanest and greenest neighborhoods.

Pittsburgh surpassed its average annual rainfall for 2018 in September

— National Weather Service

Melwood Finland

The Melwood and Finland Stormwater Project, located in the Polish Hill neighborhood, will reduce the risks of uncontrolled runoff by constructing new and improved curb lines, adding additional stormwater inlets, and installing five separate street side bioretention facilities with underground storage. These improvements are located on Finland Street, Melwood Avenue and Bethoven Streets. Additionally, new curb and gutter installations and resurfacing of Finland Street between Bigelow Boulevard and Melwood Avenue was completed in conjunction with the City's repaving schedule.

This project is nearing a fall 2018 completion. It is estimated to manage 1.2 million gallons of runoff per year. The project cost is $1.1 million.

Ribbon cutting for the stormwater project at Centre and Herron in the Hill District

Negley Run

PWSA is partnering with the Army Corp of Engineers, Pennsylvania Department of Transportation and other stakeholders to design and construct a stormwater separation project along Washington Boulevard to provide a new stormwater outfall to the Allegheny River. The project will also include wetlands development, detention and other features to reduce combined sewer overflow volume, reduce flooding, and improve water quality.

This project is in its design phase and is estimated to cost $15 million.

Mairdale Avenue Stormwater Improvement Project

The Mairdale Avenue Stormwater Improvement Project will improve the flow of stormwater through Riverview Park by using a combination of surface and subsurface green stormwater infrastructure solutions to stabilize stream banks, mitigate erosion, redirect and store stream flow, and capture stormwater runoff.

It will also decrease the occurrence of surface and basement flooding near the project area and reduce the amount of sediment and debris that often blocks the combined sewer system. The project will also enhance public amenities within the park.

Design costs for this project are approximately $1.8 million.

Hillcrest Avenue Stormwater Project

The Hillcrest Avenue Stormwater Project, located in the Garfield neighborhood, transformed a vacant lot at the corner of Hillcrest Avenue and Donna Street into a stormwater park to manage road and sidewalk runoff at the corner of Donna Street and Hillcrest Avenue. The project features two bioretention areas and underground storage within the former vacant lot. An additional bioretention area was installed at the intersection of North Atlantic and Hillcrest avenues. The bioretention areas use plantings, engineered soil and subsurface features to reduce combined sewer overflows and improve water quality.

The project was completed this summer. It is estimated to manage one million gallons of runoff per year. PWSA is working with the City of Pittsburgh and Garfield residents to incorporate fencing and garbage cans into the project. The project cost $1.3 million.

Maryland Avenue

The Maryland Ave Stormwater Project will consist of distributed green stormwater infrastructure systems in four targeted areas within the Shadyside neighborhood. This area is one of the city’s largest contributors of combined sewer overflows within the combined sewer system. Additionally, this project will help to alleviate the widespread occurrences of basement backups and street flooding throughout the neighborhood.

Design costs for this project is approximately $11 million.

Saw Mill Run

PWSA, in collaboration with 11 neighboring communities, is developing an integrated watershed management plan throughout Saw Mill Run. The Saw Mill Run Watershed is one of the first plans within the Pittsburgh region to develop a collaborative approach to managing stormwater. The plan will help spur economic development and improve the quality of life for those living and working in its surrounding neighborhoods.

Saw Mill Run currently uses traditional, end-of-pipe solutions to manage stormwater, which has led to flashy peak flows and flooding, high sediment loads from stormwater, and contributes to combined sanitary and sewer overflows. The Saw Mill Run plan will utilize a combination of techniques.

The estimated cost of this project, currently in its planning phase, is approximately $6.5 million.

Four Mile Run Stormwater Improvement Project

Four Mile Run encompasses Schenley Park and several Pittsburgh neighborhoods including Greenfield, Hazelwood, Oakland, and Squirrel Hill. These neighborhoods, like many throughout Pittsburgh, experience the impacts of stormwater that has nowhere to go.

This project will capture and route the flow of stormwater through a natural channel that will follow the path of the historic streams that formed Four Mile Run from Panther Hollow Lake to the Monongahela River. Panther Hollow Lake overflows will be redirected to discharge directly into the Monongahela River instead of the combined sewer.

Redirecting the flow of water through a natural channel will help to prevent combined sewer overflows and reduce the intensity of flooding that occurs throughout Four Mile Run.

This project is in its design phase and will cost approximately $40 million.

Rendering of Wightmant Park Stormwater Projects (click to enlarge)

Wightman Park

Through a public process that started in 2014, community members helped develop a master plan the final design for an improved Wightman Park. The planned improvements create a safer, cleaner, greener, and more accessible space for the public to enjoy.

PWSA is incorporating the stormwater components of the Wightman Park Master Plan to improve drainage and combat stormwater issues in the surrounding area. The stormwater components will redirect stormwater flow from adjacent streets into systems in the park and store stormwater in retention tanks during large storm events. Additionally, the site will be regraded to improve the flow of stormwater and includes green infrastructure solutions including an infiltration pond, and rain gardens.

Construction is anticipated to begin in 2019 and it will manage 5.4 million gallons of runoff per year. The design cost is $2.4 million.

Southside Park/21st Street

The Southside Park/21st Street Stormwater Project is being designed to manage stormwater and stream inflows that enter the combined sewer system at South Side Park and the South 21st Street corridor. The project will decrease nearby surface and basement flooding. It will also reduce the amount of sediment and debris that often blocks the combined sewer system.

As part of this project, PWSA will determine the feasibility of providing a new stormwater outfall to convey stormwater flows directly to the Monongahela River via South 18th Street instead of relying on the combined sewer system.

This project is currently in its planning and design phase and is estimated to cost $8.7 million.